The people's requirements for the quality of their living environment become higher and higher with the improvement of living standards, so that the mobile air-conditioners come into widespread use. Mobile air-conditioners have no outdoor machine, but that have an inlet pipe and an outlet pipe. Both the inlet pipe and the outlet pipe are put into the intake on the wall body while operation. This is environment-friendly and energy-conserving. However, while using the mobile air-conditioner, the outlet pipe might fall out of the intake on the wall body and cause leakage of air.